DE602004000799T2 - Ink jet printing ink and recording device - Google Patents

Description

The The present invention relates to a liquid ink and a recording apparatus. Especially The present invention relates to an ink-jet printing ink and an ink jet recording apparatus.

In a situation where a fairly large number of copies of a printed matter are required, such as in the cases of printing copies a local advertisement and a company information sheet conventionally a printing machine that uses a stencil inserted, to meet such requirements. In recent years however, has become increasingly a demand printer capable of Demand diversification and inventory minimization are increasing rapidly cope with Position of the above-described, conventional printing machine used. It is expected that an ink jet printer as such Demand printer useful Since the ink jet printer is capable of high speed and a high print quality to achieve.

Regarding successful printing of brilliant pictures using A demand printer has a known method of insertion a solvent type ink or a liquid Solvent-type toner, which both are a pigment and an organic solvent in the same way included, as in the case of a printing machine, which is a template starts. This procedure leads but to such an extent to the evaporation of the organic Solvent, which not except Eight can be left when printing with a specific frequency is repeated. When this procedure is used, arises therefore the problem of pollution due to this evaporated organic Solvent, which consequently the provision of an exhaust gas treatment plant or a solvent recovery system required.

Under these circumstances now finds a photosensitive ink and a printer system, which uses the photosensitive ink, attention as a Method, which for a overcome the problem described above is effective. In this Process hardens the photosensitive ink which reaches the surface of the Printed matter is migrated, with light off quickly. The used therein Photosensitive ink is indispensable in the typical example Components a polymer monomer radical, a photopolymerization initiator and a pigment.

There an ink layer consisting of such a photosensitive Ink was formed, directly solidified by irradiation with light is possible with the use of this printing system, one To obtain relatively high quality printed matter. The used therein Contains ink but a lot Carcinogens, such as a radical generator, and furthermore, it is a fleeting one Acrylic derivative used as a polymer monomer radical will, supreme irritating to the skin and bad smelling. In particular, this photosensitive requires Ink a careful Treatment. Further, the radical polymerization in the ink becomes strong hampered by the presence of oxygen in the atmosphere, and at the same time the light is absorbed by the pigment, which is contained in the ink. Therefore, the exposure dosage tends in a deep area of the ink layer, too insufficient become. As a result, the sensitivity of this photosensitive Ink for the light exposure is relatively low, so that a significantly advanced Exposure system is required to produce a printed matter of high quality through the use of this printer system.

Regarding overcoming These problems became a cationic curing type ink proposed, which by irradiation with an active energy beam cures. This cationic curing type ink can be used in such a manner Manner be used from an inkjet printhead is output, for example, a pattern of the ink layer according to a desired Picture on a record carrier and then the resulting ink layer becomes irradiated subjected to active energy, such as ultraviolet Beams or an electron beam to cure the ink layer.

However, there is a problem common to all types of photo cationic curing type ink jet inks that the viscosity of the ink fluctuates considerably over time. The reason for this can be attributed to the fact that the ink is quite susceptible to a dark reaction. When the viscosity of the ink fluctuates, the trajectory of the ink is disturbed, and the reproducibility of the printing is adversely affected particularly in the case of the ink-jet printing ink. In the worst case, it causes critical situations to occur, such as an output defect or clogging of the ink. Therefore, the viscosity fluctuation of the ink is one of the very serious problems. So far, no one has succeeded in providing an effective means of solving this viscosity increase problem of the inkjet ink Find.

Inkjet inks of the photocationic curing type, which is a compound containing an oxirane group, a compound which an oxetane ring contains a vinyl ether compound, a pigment, a pigment dispersant, a photoacid generator and other additives are for the occurrence of a viscosity fluctuation (Viscosity increase) with the time in a big one Magnitude due to the dark reaction of inkjet inks, which is pretty distinctive. That's why the inkjet inks are of photo cationic curing type poorly storable and consequently have a short useful life.

It Therefore, one of the objects of the present invention is an ink-jet printing ink to provide an excellent storability and is capable of reliably producing high quality printed matter with excellent To achieve reproducibility.

A Another object of the present invention is to provide an ink-jet recording apparatus which is capable, reliable High quality printed matter produce with excellent reproducibility.

According to one aspect of the present invention, there is provided an ink-jet printing ink comprising:
a first solution containing a solvent which is polymerizable in the presence of an acid and a colorant dispersed in the solvent; and
A second solution containing a photoacid generator capable of generating an acid upon its irradiation with light and prepared separately from the first solution, wherein the second solution is preserved separately from the first solution.

According to another aspect of the present invention, there is provided an ink-jet recording apparatus comprising:
a color ink tank having a capacity V1 harboring a solvent therein, which is polymerizable in the presence of an acid and a colorant dispersed in the solvent;
a reaction liquid container having a capacity V2 (V2 <V1) housing therein a reaction liquid having a solvent and a photo-acid generating agent dissolved in the solvent and capable of generating an acid when irradiated with light;
a stirring vessel which mixes the color ink and the reaction liquid in a mixing ratio of S1: S2 (color ink: reaction liquid) to prepare a recording ink;
a color ink supplying agent which feeds the color ink from the color ink tank into the stirring tank;
a reaction liquid supply means which feeds the reaction liquid from the reaction liquid container into the stirring container;
an ink-jet recording head which outputs the recording ink on a recording medium; and
a delivery tube which feeds the recording ink into the recording head.

These Summary of the invention does not necessarily describe all force Characteristics, so that the invention also a sub-combination of these may be described features.

The Invention can be more complete from the following detailed Description be understood, if this in conjunction with the accompanying drawings, in which:

1 Fig. 10 is a diagram schematically illustrating an ink-jet recording apparatus according to an embodiment of the present invention;

2 Fig. 10 is a block diagram for illustrating the control system of the ink jet recording apparatus incorporated in 1 will be shown;

3 Figure 12 is a graph illustrating the viscosity increase of a recording ink over time;

4 Figure 12 is a graph illustrating the viscosity increase of a recording ink over time;

5 Figure 12 is a graph illustrating the viscosity increase of a recording ink over time;

6 Fig. 12 is a graph for illustrating the relationship between the rate of change of the viscosity of the ink and the rate of change of the output volume of the ink;

7 Fig. 12 is a graph for illustrating the influence of temperature on the change in viscosity of an ink composition; and

8th Fig. 10 is a diagram schematically illustrating a prior art ink jet recording apparatus.

When next be different embodiments of the present invention explained in detail below.

The Ink jet printing ink according to a embodiment The present invention is formed from two solutions which are separated should be prepared and preserved separately. A first solution has a solvent which is polymerizable in the presence of an acid and a colorant which is in the solvent is dispersed while a second solution a photoacid generator contains which is capable of generating an acid when irradiated with light, wherein the photoacid generator in a solvent disbanded is.

If This ink jet printing ink in an ink jet recording apparatus according to embodiment used in the present invention, these two Solutions, which each in separate containers were preserved separately, just before introduction into An ink jet type recording head is mixed with each other. After sufficient mixing with each other by stirring the ink, which consists of a mixture of these two solutions, namely fed to the recording head of the ink jet type and on a record carrier output. The ink, which for this output is ready is referred to in this specification as a "record ink".

The Recording ink is output on a record carrier, so as to form an ink layer pattern which is a desired one Picture corresponds. When irradiating this ink layer with light an acid from the photoacid generator produced, this acid thus enabled is used as a catalyst for the crosslinking reaction of the polymerizable compound (solvent) to act. Furthermore, the acid thus produced diffuses into the Ink layer. Furthermore, the crosslinking reaction in the state, in which the acid is diffused and used as a catalyst by heating the Ink layer can be accelerated. In contrast to a radical polymerization This crosslinking reaction can not be due to the presence of oxygen be hampered. It is therefore possible to allow several Crosslinking reactions take place with a single photon, where by it possible is to perform the crosslinking reaction with high sensitivity. In addition is it is possible the crosslinking reaction even in a deep area of the ink layer or in the interior of the light-absorbing recording medium quickly to be held.

If this record ink is used accordingly, it is possible, the ink layer by the irradiation with light and heating after forming an ink layer by discharging it onto the surface of a Solidify printed matter quickly. In particular, it is now possible, one Printed matter of high quality without a fairly advanced exposure system to make necessary.

According to this embodiment Further, the above-described polymerizable compound becomes more as at least part of the solvent used, and typically represents a polymerizable Compound almost all the solvent. If in this way the ratio a polymerizable compound in the solvent is sufficiently high, is the possibility low that an organic solvent volatilizes during the printing process. Therefore, the problem may be due to the contamination of the atmosphere the volatilization overcome the organic solvent thus providing an exhaust treatment plant or a solvent recovery system is bypassed.

In addition, according to this embodiment, it is no longer necessary to use an organic solvent, and further, the ink layer can be solidified quickly. As a result, an image can be easily fixed on printing surfaces having various different characteristics without causing substantial generation of bleeding. It is also possible to suppress the deterioration of the printing area which might otherwise be caused to occur accompanying the drying process of the ink layer. Further, since the ink jet printing ink according to this embodiment is capable of containing a high concentration of a pigment as a coloring component, it is possible to provide a printing pattern which is quite sharp and has excellent aging resistance.

When next all solutions, which the ink-jet printing ink according to this embodiment of the constitute the present invention, explained in detail.

The first solution has a solvent which is polymerizable in the presence of an acid and a colorant which is in the solvent is dispersed, this first solution also referred to as a color ink becomes.

For the solvent, which in the presence of an acid is polymerizable, it is possible Compounds with a viscosity of 30 mPa · s or less under conditions of ordinary temperature and atmospheric pressure and having a boiling point of 150 ° C or more, preferably with a boiling point of 180 ° C or more. Particularly preferred examples of such Compounds include those having a molecular weight of not more than 1000 and at least one cyclic ether group, such as an epoxide group, oxetane group, oxolane group, etc. It is further also possible, acrylic or vinyl compounds having the above-described substituent groups on their side chains; Carbonate-based compounds; Melanin connections low molecular weight; Monomers having a cationically polymerizable vinyl bond, such as for example, vinyl ethers, vinylcarbazoles, styrene derivatives, alpha-methylstyrene derivatives and vinyl alcohol esters, such as esters of vinyl alcohol and Acrylic acid, methacrylic acid, etc. to use together.

Under These compounds are polymerizable compounds which are known in are able to crosslink in the presence of an acid, and by an aliphatic backbone or alicyclic backbone be formed, thereby advantageous that when these polymerizable Compounds together with the others described above Components are used, the transparency of the recording ink is improved in the exposure step, and further it is possible, the Ink layer after curing with a suitable degree of thermoplasticity and a suitable To provide separability. As a result, the sensitivity, the Fixing property, the transfer characteristic and preservation of the color ink can be improved. Especially if Epoxy compounds having an alicyclic backbone as one polymerizable compound used, it is in addition to an improved reactivity possible, to increase the boiling point of the ink to a certain extent while a low viscosity the ink is retained.

on the other hand is it in a situation where it is especially needed is the cure speed the ink according to this embodiment to accelerate the present invention, in which, for example a high printing speed of up to several tens of meters per Minute is required, desirable Oxetane compounds use. Since the oxetane compounds in the Are capable of curing to promote the ink and to speed up, the primary curing of the ink can be accelerated become. However, in this case, since lowering the thermoplasticity of the ink causes their heat transfer property tends for the deterioration, since the amount of the added oxetane compounds is increased. Therefore, the amount of oxetane compounds should preferably be within the range of 10 to 40 parts by weight based on the total amount of the solvent lie. If more or less oxetane compounds than this range to be added is curing the ink does not accelerate or else likely leads for clogging the nozzle or inadequate thermoplasticity of the ink.

specific Examples of oxetane compounds used herein can, include 1,4-bis-1-ethyl-3-oxetanylmethoxybenzene, 1,3-bis-1-ethyl-3-oxetanylmethoxybenzene, 4,4'-bis-3-ethyl-3-oxetanylmethoxybiphenyl, Phenol novolacoxetane, Oxetanylsilseschioxan, Allonoxetan OXT-101 and OXT-102 (Toa Gosei Co., Ltd.), 1,4-bis-1-ethyl-3-oxetanylmethoxycyclohexane, 1,4-bis-3-ethyl-3-oxetanylmethoxycyclohexan, 1,2-bis-1-ethyl-3-oxetanylmethoxynorbornan, aliphatic or alicyclic compounds having at least two Oxetane groups and acrylic or methacrylic compounds with a Oxetane group on their side chains.

If It is necessary to increase the viscosity of the ink in addition to the need to reduce the curing rate of the ink to increase, For example, it is preferable to further include a vinyl ether compound in the ink. If a vinyl ether compound is included in the ink, can the cure speed The ink can be improved without the volatility of the ink extremely increase, and at the same time, the viscosity of the ink can be lowered.

When such a vinyl ether compound, it is possible compounds having a Vinyl group, which by an ether bond to a (p + 1) -valent group which has a benzene ring, a naphthalene ring and a biphenyl ring; or on a (p + 1) -valent group consisting of a cycloalkane backbone, Norbornan main chain, Adamantane backbone, tricyclodecane backbone, tetracyclododecane backbone, Terpenoid main chain and cholesterol main chain is derived. It is possible in particular with polyvinyl etherified compounds of cyclohexane, norbornane, Tricyclodecane, adamantine, benzene or naphthalene.

If it is necessary to print a product with solvent resistance, such as alcohol resistance, when using the ink composition according to the embodiment of the present invention To provide invention, it is preferred to connect with an aromatic main chain. Since it is possible by using a compound with an aromatic backbone the curing to promote and to speed up, the durability of the printed matter is improved. Among the compounds having an aromatic main chain it is more preferably, oxetane compounds having an aromatic main chain whose Valence is 2 or more, or vinyl ether compounds with one use aromatic main chain whose valence is 2 or more is. Specific examples of such oxetane compounds include 1,4-bis-1-ethyl-3-oxetanylmethoxybenzene, 1,3-bis-1-ethyl-3-oxetanylmethoxybenzene, 4,4'-bis-3-ethyl-3-oxetanylmethoxybiphenyl, Phenol novolacoxetane and alicyclic compounds with at least two oxetane groups.

The first solution may take a small amount of a high viscosity compound as part of the solvent containing specific examples of such a compound those with a relatively high molecular weight and those include which are solid at normal temperatures. If this type of connection additionally Included in the ink may be the flexibility of the ink layer after curing or the dispersibility the pigments are improved. If in this case further a Connection with a big one Number of valences and high reactivity is set, it is possible, the Hardness and the solvent resistance the derived, hardened To improve products.

Examples Such a viscous compound includes compounds which a molecular mass of not more than 5000 and which have a cyclic ether group such as an epoxy group, oxetane group, Oxolan group, etc., which are bound by a long-chain alkylene group are; Acrylic or vinyl compounds as described above Substituent groups on their side chains; Carbonate-based compounds; Low molecular weight melanin compounds; Monomers with cationic polymerizable vinyl bond; and oligomers resulting from the polymerization derive from one or more such monomers; specific examples of such monomers and oligomers include Vinyl ethers, vinylcarbazoles, styrene derivatives, alpha-methylstyrene derivatives and vinyl alcohol esters, such as esters of vinyl alcohol and acrylic acid, methacrylic acid, etc..

In addition to the compounds described above, the solvent, which is the first solution a homopolymer or a copolymer of the vinyl alcohol; Acid-reactive / dehydrocondensing Resins with an OH group, COOH group, acetal group, etc., whose molecular mass 5000 or less; Acid-reactive / dehydrocondensing Polycarbonate resins, their molecular mass 5000 or less; Copolymers resulting from a reaction between polyamic acid, polyamino acid or acrylic acid and a vinyl compound having an acid-polymerizable double bond are derived on their side chain; Copolymers, which consist of a Reaction between vinyl alcohol and a vinyl compound with a Acid-polymerizable Derive double bond on its side chain; and methylolmelamine resin contain.

Since the ink according to this embodiment of the present invention is a photosensitive ink which must be heated, the volatility of the ink should preferably be as low as possible in terms of safety and smell. For example, the volatilization rate of the ink after its exposure process and at a temperature of 80 ° C should preferably be not higher than 0.2 mg / cm ² · min. The volatilization amount herein represents an amount (mg) of volatilized ink per minute as measured when heating a container containing the ink and having an opening area of 10 cm ² . Although this volatilization value varies depending on the size of the opening of the container, it is generally defined by measuring a value under the condition where 4 g of the ink is placed in a 6 cm diameter Petri dish and heated under atmospheric pressure , If the ink is formulated to fall outside this range of volatiles, the volatilization rate of the ink in its heating step is too high, so that environmental protection is impaired and the odor problem becomes serious. On the other hand, when the volatility of the ink is extremely low, for example For example, when the volatilization speed of the ink is 0.00001 mg / cm ² · min or less, the viscosity of the ink generally becomes too high, so that the discharge of the ink jet is difficult in most cases.

If the ink layer after curing has sufficient thermoplasticity and separability, Is it possible, to allow this ink layer to transfer to a recording medium is issued after a recording ink is output on an image carrier was to form the ink layer. In particular, first of all an ink layer by discharging a recording ink on the Image carrier formed, and the resulting ink layer becomes a Lichtbe radiation and a warming to cure or preliminarily cure the ink layer. Then be under the condition in which a record carrier with a record carrier is kept in contact, only applied pressure or both pressure and heating, to reflow the ink layer or the ink layer to plasticize. As a result, the ink layer becomes one Transfer record carrier. If otherwise desired is that the recording ink is output directly on a record carrier At first, an ink layer is formed on the recording medium and then subjected to light irradiation and heating to the ink layer cure or provisionally cure. Then, the resultant ink layer is further subjected to heating, around the ink layer completely cure, thus allowing is to fix the ink layer on the recording medium.

If a compound which has an aliphatic main chain or an alicyclic Having a main chain each having a cyclic ether group, such as an epoxide group, oxetane group and oxolane group, as the above-described polymerizable compound is used, it is basically possible, the ink layer after the curing process the ink layer with a suitable degree of thermoplasticity and separability provide. It is particularly preferred to be polymerizable Use compounds which have an epoxide group and an excellent Acid polymerizability exhibit. Examples of such compounds include those with a bivalent aliphatic or alicyclic hydrocarbon group with 1 to about 15 carbon atoms or those with an epoxy group or a alicyclic epoxide group on one or both bivalent groups, which partially an aliphatic chain or an alicyclic Have main chain.

Although there are no particular restrictions on the number of epoxide groups introduced into the above-described molecular backbone, it is preferred that the number of valences should be at most two or three to make the ink layer flexible and releasable after it has been cured provide. As examples of such polymerizable compounds, the compounds represented by the following general formulas (1) and (2) can be used. RI-A1-R2 (1) R3-A2 (2)

at In these general formulas (1) and (2), R1, R2 and R3 represent individual ones Epoxide groups or epoxide groups having an alicyclic backbone; and represent A1 and A2 each a functional group.

The Compounds represented by the general formulas (1) and (2) are generally low in viscosity, i. in the range of 1 cP to about 30 cP. Therefore, the admixture of these compounds is lower viscosity into the ink to sufficiently lower the viscosity of the ink effective.

Further, the alicyclic epoxy compounds represented by the following general formula (3) generally have a high viscosity, ie, in the range of from 20 cps to about 500 cps. Therefore, incorporation of these high viscosity compounds into the ink is effective to provide the ink layer with flexibility or, on the contrary, with hardness. R4-A3- (R5) _k (3)

at of this general formula (3), R4 and R5 represent individual ones Epoxide groups or epoxide groups having an alicyclic backbone; and A3 represents a (k + 1) -valent functional group (k is a natural number) with at least one alkylene group and / or one alicyclic Backbone.

The compounds described above with lower or higher viscosity should preferably be used in such a way that at least one compound combined with low viscosity mixed with at least one compound of high viscosity become. For example, if 5 to 90 parts by mass of a compound with low viscosity with 1 to 40 parts by weight of a high viscosity compound per 100 Mass parts of the first solution mixed, it is advantageous to realize a least, minimal fluidity, which for the Output of the ink is required (i.e., a viscosity of 30 cp or less at a temperature of 50 ° C). It is particularly preferred the compounds represented by the general formulas (1) and (2) represents be, with the compounds, which by the general formula (3) represents be, in a mass ratio of about 1: 1 to 10: 1 to mix.

When examples for the aliphatic epoxy compounds described above is it possible alicyclic Epoxy compounds such as celloxide 2021, celloxide 2021A, celloxide 2021P, celloxide 2081, celloxide 2000 and celloxide 3000 (DAICEL Chemical Industries Ltd.); (Meth) acrylate compounds with epoxide group, such as cyclomer A200 and cyclomer M100; Methacrylate having a methylglycidyl group, such as MGMA, Glycidol, which is a low molecular weight epoxide compound represents; β-methylepichlorohydrin; α-pinene oxide; α-Olefinmonoepoxid with 12 to 14 carbon atoms; α-olefin monoepoxide with 16 to 18 carbon atoms; epoxidized soybean oil such as Dimac 5-300K; epoxidized linseed oil, such as Dimac L-500; and polyfunctional epoxide compounds, such as Epolead GT301 and Epolead GT401, use. It is also possible, alicyclic epoxide compounds (such as Cylacure; Dow Chemical Co., Ltd., USA); Phenolic compounds low molecular weight, which are hydrogenated and aliphatized, with their terminal hydroxyl group substituted by a group with epoxide; Glycidyl ether compounds aliphatic alcohol / alicyclic alcohol, such as Ethylene glycol, glycerine, neopentyl alcohol, hexanediol, trimethylolpropane; and glycidyl esters of hexahydrophthalic acid or hydrogenated, aromatic, polyvalent carboxylic acid use. Furthermore, the chemical resistance of the printed image for example, the ink can be epoxidized polybutadiene, such as Epolead PB3600 and PB3600M (trademarks, DAICEL Chemical Industries, Ltd.); or transparent, liquid epoxy resins with excellent aging resistance and high Tg, like for example, EHPE3150 and EHPE3150CE (Trademark, DAICEL Chemical Industries, Ltd.). In addition to these epoxy resins, it is too possible, to include a lactone-modified alicyclic epoxy resin, examples of which are Placcell GL61, GL62, G101, G102, G105, G401, G402, G403 and so on.

Under these are in terms of viscosity and volatility preferred to use celloxide 2000, celloxide 3000 or compounds, which results from the modification of alcohols, such as α-pinene oxide ethylene glycol, Glycerol, neopentyl alcohol and hexanediol, to derive glycidyl ethers are.

If the alicyclic backbone contained in the epoxy compounds is having a terpenoid main chain, the safety of the Ink layer after curing with regard to the human body or human environments. Examples of epoxy compounds include epoxidized compounds resulting from the oxidation of a unsaturated Derive binding of terpene-based compounds with unsaturated bonds such as myrcene, ocimen, geraniol, nerol, linalol, Citrorenol, citral, menthene, limonene, dipentene, terpinolene, terpinene, Phellandren, Sylvestren, Piperithol, Terpineol, Menthenmonol, Isopregol, Peraryaldehyde, piperitone, dihydrocarvone, carvone, pinole, ascaridol, Sabinen, Careen, Pinene, Bornen, Fenchen, Camphene, Carveol, Sesquiterpen, Diterpen, Triperpen etc .. Furthermore, epoxy compounds, which derive from the oxidation of norbornene compounds, which in a big one Amount present in nature, beneficial in terms of the Costs.

Incidentally, can the oxidation of the compounds described above to epoxy compounds be carried out using different oxidation methods, which use an oxidizing agent such as peracetic acid. Among them is an air oxidation process which is N-hydroxyphthalimide and a rare earth catalyst, as in Japanese Patent Publication (Kokai) No. 11-49764 (1999), for Use in this case best suited.

The compound to be polymerized in the presence of the above acids may be appropriately selected depending on the photo-acid generating agent contained in the second solution, which will be explained hereinafter. In this case, the amounts of all the components should be properly adjusted so as to allow a recording ink to contain predetermined amounts of these components. For example, if a compound to be polymerized in the presence of an acid in the first solution should be formed by a mixture consisting of 30 to 70 parts by weight of an alicyclic epoxide compound having a terpenoid backbone or from norbornane and 30 to 70 parts by mass of an epoxy compound having an aliphatic backbone having two or more glycidyl ether groups each having not more than 6 carbon atoms, a color component in a proportion of 1 to 10 parts by mass may be included in the ink. As the photo-acid generating agent in the second solution, it is preferable to use a hexafluorophosphate compound having a phenylsulfonium main chain and to mix the first solution and the second solution in such a manner that the content of the photo-acid generating agent in the recording ink 1 to 10 parts by mass will be. If the ink is formulated in this way, it is possible to provide the ink not only with excellent photosensitivity but also with proper hardness, adhesion and transfer properties.

When the alicyclic epoxide compounds, it is possible limonene (di) oxide, (di) oxabicycloheptane and to use their substituted compounds. Specific examples the epoxide compounds with not more than 6 carbon atoms include neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, Glycerol diglycidyl ether, glycerol triglycidyl ether, 1,6-hexanediol diglycidyl ether etc .. Among these is a combination of limonene dioxide with neopentyl glycol diglycidyl ether most preferred. If otherwise exceeds the number of carbon atoms in the epoxy compounds 6, can the hardness, the adhesion and the transmission characteristics of the ink deteriorate.

If an epoxy compound consisting of the above combination is formed, the ink layer which has been cured, during their warming to at least a temperature of 50 ° C, more preferably to 80 ° C or more, in which the fixing and transfer the ink layer can be carried out properly, be re-liquefied. In this case, the ink layer which has been cured, as liquid Ink or in an organic solvent, which lower alcohol, such as relatively stable ethanol, is formed, or from mineral oil components with low boiling point, such as Isoper formed becomes. Accordingly, it is possible that Occurrence of clogging of the nozzle to suppress or if the blockage of the nozzle The obstruction can even be easily resolved. In particular, the maintenance of the nozzle head can be greatly improved.

however The properties differ from the printed matter be required, depending of their intended use. For example, if the printed matter for the Front of a can or a PET (polyethylene terephthalate) bottle or for the front of a container is to be used, which is formed from oils, can the first solution, additionally to the above-described epoxy compounds, compounds with a phenolic hydroxyl group, such as glycidyl ether compounds of bisphenol A, glycidyl ether compounds of a phenolic oligomer, such as for example phenol novolac and polyhydroxystyrene, ordinary aromatic epoxide compounds, such as styrene oxide, or oxetane compounds having an aromatic main chain. In order to improve the density of crosslinking, the first solution may alternatively at least trivalent epoxy compounds or at least trivalent Contain vinyl ether compounds.

The first solution can by dispersing a color component in a solvent which are prepared in the presence of those described above acids is polymerizable.

When the color components it is possible Use pigments and / or dyes. However, in this embodiment of the present invention acids are used for use in the place of pigments Dyes more preferably, which are easily by the effects of acids discolour can.

When the pigments which are useful as a color component in this case there is no specific restriction as long as they use the light coloring and tinting properties which are required by the pigments. The in this Case to be used pigments further with other properties, such as magnetism, Fluorescence, conductivity, dielectric property, etc. in addition to the dyeing and toning properties to be provided. If the pigments with these different Properties can be provided, it can be possible to use a picture with to get different functions. Furthermore, the pigments may be particles which effectively comprises an ink layer having increased heat resistance or increased physical strength provide.

Examples of the pigments which are useful in this case include, for example, light absorption pigments. Specific examples of such light absorption pigments include a carbon-containing pigment such as carbon black, refined carbon and carbon nanotubes; metallo xid pigments such as iron black, cobalt blue, zinc oxide, titanium oxide, chromium oxide and iron oxide; Sulfide pigments such as zinc sulfide; Phthalocyanine pigments; Pigments formed from salts such as metal sulfate, metal carbonate, metal silicate and metal phosphate; and pigments formed from metal powder, such as aluminum powder, bronze powder and zinc powder.

Examples The pigments further include, for example, dye chelate (Chelat basic dye type, acid dye-type chelate, etc.); Nitro pigments; Nitroso pigments (including aniline black, naphthol green B), azo pigment (including Azo varnish, insoluble Azo pigment, condensed azo pigment, chelate azo pigment), such as for example Bordeaux 10B, red 4R and chrome-phthal red; Paint pigments, such as Peacock Blue Lacquer and Rhodamine Lacquer; Phthalocyanine pigments, such as phthalocyanine blue; polycyclic pigments (such as for example perylene pigment, perinone pigment, anthraquinone pigment, Quinacridone pigment, dioxane pigment, thioindigo pigment, isoindolinone pigment, Quinophthalene pigment, etc.); Thren pigments, such as Thioindigo red and Indanthrone blue; Quinacridin pigment; and organic pigments, such as for example, isoindolinone pigment.

Examples the pigments which are used in a black ink can, include carbon black, such as Raven 5750, Raven 5250, Raven 5000, Raven 3500, Raven 1255 and Raven 700 (Colombia Co., Ltd.); Regal 400R, Regal 330R, Regal 660R, Mogul L, Monarch 700, Monarch 800, Monarch 880, Monarch 900, Monarch 1000, Monarch 1100, Monarch 1300 and Monarch 1400 (Cabot Co., Ltd.); No. 2300, No. 900, MCF88, # 33, # 40, # 45, # 52, MA7, MA8, MA100 and # 2200B (Mitsubishi Chemical Co., Ltd.); Color Black FW1, Color Black FW2, Color-Black FW2V, Color-Black FW18, Color-Black FW200, Color Black S150, Color Black S160, Color Black S170, Printex 35, Printex U, Printex V, Printex 140U, special black 6, special black 5, Special Black 4A, Special Black 4 (Dexa Co., Ltd.).

Examples pigments which can be used in a yellow ink Yellow 128, C.I. Pigment Yellow 129, C.I. Pigment Yellow 151, C.I. Pigment Yellow 154, C.I. Pigment Yellow 1, C.I. Pigment Yellow 2, C.I. Pigment Yellow 3, C.I. Pigment Yellow 12, C.I Pigment Yellow 13, C.I. Pigment Yellow 14C, C.I. Pigment Yellow 16, C.I. Pigment Yellow 17, C.I. Pigment Yellow 73, C.I. Pigment Yellow 74, C.I. Pigment Yellow 75, C.I. Pigment Yellow 83, C.I. Pigment Yellow 93, C.I. Pigment Yellow 95, C.I. Pigment Yellow 97, C.I. Pigment Yellow 98, C.I. Pigment Yellow 114, and C.I. Pigment Yellow.

Examples pigments which can be used in a magenta ink C.I. Pigment Red 123, C.I. Pigment Red 168, C.I. Pigment Red 184, C.I. Pigment Red 202, C.I. Pigment Red 5, C.I. Pigment Red 7, C.I. Pigment Red 12, C.I. Pigment Red 48 (Ca), C.I. Pigment Red 48 (Mn), C.I. Pigment Red 57 (Ca), C.I. Pigment Red 57: 1, and C.I. Pigment Red 112th

Examples for the Pigments, which are in a cyanine ink can be used further include C.I. Pigment Blue 15: 3, C.I. Pigment Blue 15:34, C.I. Pigment Blue 16, C.I. Pigment Blue 22, C.I. Pigment Blue 60, C.I. Pigment Blue 1, C.I. Pigment Blue 2, C.I. Pigment Blue 3, C.I. Vat Blue 4, and C.I. Vat Blue 60.

Further it is also possible white Pigments, such as natural alumina, metal carbonates, such as lead white, Zinc white and magnesium carbonate; Metal oxides, such as barium and titanium. The recording ink containing white pigments can not only in white printing but also when printing corrections or when submitting images by overwriting be used.

As phosphor pigments, it is possible to use inorganic fluorescent substances but also organic fluorescent substances. Specific examples of the inorganic fluorescence include MgWO ₄ , CaWO ₄ , (Ca, Zn) (PO ₄ ) ₂ : Ti ⁺ , Ba ₂ P ₂ O ₇ : Ti, BaSi ₂ O ₅ : Pb ²⁺ , Sr ₂ P ₂ O ₇ : Sn ²⁺ , SrFB ₂ O _3.5 : EU ²⁺ , MgAl ₁₆ O ₂₇ : Eu ²⁺ , and inorganic acid salts such as tungstate and sulfate. Specific examples of the organic fluorescent agents include acridine orange, aminoacridine, quinacrine, anilino-naphthalenesulfonate derivatives, anthroyloxystearic acid, auramine O, chlortetracycline, cyanine dye such as merocyanines and 1,1'-dihexyl-2,2'-oxacarboxycyanine, dansylsulfonamide, dansylcholine , Dansylgalactoside, dansyltolidine, dansylchloride derivatives such as dansyl chloride, diphenylhexatriene, eosin, ε-adenosine, ethidium bromide, fluorescein, foamycin, 4-benzoylamide-4'-aminostilbene-2,2'-sulphonic acid, β-naphthyltriphosphoric acid, oxonol Dye, parinaric acid derivatives, perylene, N-phenylnaphthylamine, pyrene, safranine O, fluorescamine, fluorescein isocyanate, 7-chloronitrobenzo-2-oxa-1,3-diazole, dansylaziridine, 5-iodoacetamidoethylaminonaphtha lin-1-sulfonic acid, 5-iodofluorescein, N-1-anilinaphthyl-4-maleimide, N-7-dimethyl-4-methylcumanylmaleimide, N-3-pirenemaleimide, eosin-5-iodoacetamide, fluorescein mercuric acetate, 2-4'-2 '' Ioacetamidoaminonaphthalene-6-sulfonic acid, eosin, rhodamine derivative, organic EL dye, organic EL polymer, organic EL crystal, and organic EL dendrimer.

Examples for the Powder which is used to improve heat resistance and physical strength the ink layer to be used include oxides or nitrides of Aluminum and silicon, filler and silicon carbide. For the purpose, the ink layer with electrical conductivity In addition, the ink may further comprise conductive carbon pigment, Carbon fibers or powders of copper, silver, antimony and others Contain precious metals. Iron oxide powder and ferromagnetic powder are suitable for use, the magnetic ink layer To provide property. It is also possible to use metal oxide powders, such as Tantalum oxide or titanium oxide, with high dielectric constant in to include the recording ink.

It is possible, too, Include dyes as an auxiliary component of the pigment in the ink. dyes for example, which have a low acidity and basicity and a excellent solubility in epoxy such as azo dye, sulfur dye (building materials), Disperse dye, fluorescent whitener and oil-soluble Dye, can generally used. Among these, it is more preferable an oil-soluble Dye such as azo dye, triarylmethane dye, Anthraquinone dye and azine dye. Specific examples such an oil-soluble dye include C.I. Sovent Yellow 2, 6, 14, 15, 16, 19, 21, 33, 56, 61 and 80; Diaresin Yellow A, F, GRN and GG; C.I. Solvent Violet 8, 13, 14, 21 and 27; C.I. Disperse Violet 1; Sumiplast Violet RR; C.I. Solvent Blue 2, 11, 12, 25 and 35; Diaresin Blue J, A, K and N; Orient Oil Blue IIN, 603; and Sumiplast Blue BG.

These The above-described pigments and dyes may be used singly or in combination of two or more. For the purpose improving light absorption, saturation and color vision can these pigments and dyes are used together. To further To improve the dispersibility of the pigments, the Pigments treatments for their association with a polymer binder or subjected to microencapsulation.

Of the Content of these pigments in the ink according to this embodiment The present invention should preferably be within the range from 1 to 25% by mass. If the content of these pigments is below 1 Masseliegt, the color density is too low. If, on the other hand, the Content of these pigments over 25% by mass, the output characteristic of the Ink. The content of the powder components in the ink should preferably be within the range of 1 to 50% by mass. If the salary the powder components is below 1 mass%, it is difficult to obtain sufficient Improvement effects on the sensitivity of the ink to be expected. On the other hand, if the content of the powder components exceeds 50 mass% is, the resolution and the sensitivity deteriorates the ink. The content of these additives in the first solution should be optionally selected be that enabled is that the recording ink mixed with the second solution contains suitable amounts of these pigments, etc., which are defined above are.

Of the Particle diameter of these pigments and dyes should be so small as possible be. In general, it is an average particle diameter of these pigments and dyes to not more than 1/3, more preferably to no more than about Limited by 1/10 of the diameter of the nozzle opening, through which the recording ink is output. Incidentally, is the diameter of the nozzle opening typically not bigger than 10 μm and more preferably not greater than 5 μm. Therefore should be a preferred particle diameter of these pigments and dyes not bigger than 0.35 μm if they are to be used in the printing ink.

For the purpose of improving the dispersibility of the pigments, etc., the first solution may contain a small amount of dispersants, such as nonionic or ionic surfactants and antistatic agents. It is also possible to use suitable polymer type dispersants, such as acrylic and vinyl alcohol, having similar properties to the surface active agents described above. However, if it is desired to use a cationic dispersant as a dispersant, it is advisable to select those having a lower acidity than those of the carboxylic acids because some cationic dispersants promote the dark reaction to cure the ink. Further, since dispersants and dyes having strong basicity not only deteriorate the sensitivity of the ink, but also promote the dark reaction to cure the ink, these dispersants and dyes should be selected from those which are almost neutral in nature or non-ionic.

The first solution, which contains a color component, should preferably be formulated so that it also has a basic Compound and / or a basicity adjusting compound as a the viscosity contains stabilizing agent. If carbon black is used as a color component, then the effect of this the viscosity stabilizing agents further promoted. As the basic compound Further, at the same time, not only the inside of the ink-jet head of the recording device to protect effectively but also the metal portions of the lead connection for the ink against erosion by acids the use of the basic compound in all types of inkjet inks according to this embodiment of the present invention.

When the basic compound makes it possible to use inorganic basic substances and basic organic substances, which are able to be resolved in a connection which in the presence of an acid should be polymerized. In terms of solubility, the use is more basic organic substances more preferred. Specific examples of such basic organic substances include an ammonia compound, ammonium compounds, substituted or unsubstituted alkylamine, substituted or unsubstituted aromatic amine, pyridine, pyrimidine and organic amines having a heterocyclic backbone, such as for example imidazole. More specific examples of such basic organic substances include n-hexylamine, dodecylamine, aniline, dimethylaniline, Diphenylamine, triphenylamine, diazabicyclooctane, diazabicycloundecane, 3-phenylpyridine, 4-phenylpyridine, lutidine, 2,6-di-t-butylpyridine and sulfonyl hydrazides, such as 4-methylbenzenesulfonylhydrazide, 4,4'-oxy-bis-benzene sulfonyl hydrazide and 1,3-benzenesulfonylhydrazide. It can also contain ammonium compounds be used as a basic compound. This basic Connections can used singly or in combination of two or more species become.

If but in this case a basic compound, which is a very strong basicity such as imidazole, can be used with the time an occurrence of a polymerization is caused or otherwise it is likely that a page reaction, such as For example, a decomposition of the photoacid generator takes place. On the other hand, in this case, if a basic compound which is a very weak basicity is used, it is difficult to stabilize the effect on the viscosity the ink by the addition of the basic compound sufficient to secure. The dissociation constant of the base pKb of the basic Compound at a temperature of 25 ° C and under the condition in which the basic compound is in a state of suitable aqueous solution is, should preferably be 4 or more. If at one basic compound, however, this pKb is greater than 11 is one such Compound unable to have the stabilizing effect on the viscosity to show the ink. Examples of basic compounds which are described in are able to meet the conditions described above, are Pyridine derivatives, aniline derivatives, aminonaphthalene derivatives, others Nitrogen-containing heterocyclic compounds and their derivatives.

specific Examples of the pyridine derivatives include 2-fluoropyridine, 3-fluoropyridine, 2-chloropyridine, 3-chloropyridine, 3-phenylpyridine, 2-benzylpyridine, 2-formylpyridine, 2-2'-pyridylpyridine, 3-acetylpyridine, 2-bromopyridine, 3-bromopyridine, 2-iodopyridine, 3-iodopyridine and 2,6-di-tert-butylpyridine.

specific Examples of aniline derivatives include aniline, 4-p-aminobenzoylaniline, 4-benzylaniline, 4-chloro-N, N-dimethylaniline, 3-5-dibromoaniline, 2,4-dichloroaniline, N, N-dimethylaniline, N, N-dimethyl-3-nitroaniline, N-ethylaniline, 2-fluoroaniline, 3-fluoroaniline, 4-fluoroaniline, 2-iodoaniline, N-methylaniline, 4-methylthioaniline, 2-bromoaniline, 3-bromoaniline, 4-bromoaniline, 4-bromo-N, N-dimethylaniline, 2-chloroaniline, 3-chloroaniline, 4-chloroaniline, 3-chloro-N, N-dimethylaniline, 3-nitroaniline, 4-nitroaniline, 2-methoxyaniline, 3-methoxyaniline, Diphenylamine, 2-biphenylamine, o-toluidine, m-toluidine, p-toluidine, 3,3'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone and 4,4'-bis-4-aminophenoxydiphenylsulfone.

specific Examples of the aminonaphthalene derivatives include, for example, 1-amino-6-hydroxynaphthalene, 1-naphthylamine, 2-naphthylamine, diethylaminonaphthalene and N-methyl-1-naphthylamine.

specific Examples of other nitrogen-containing heterocyclic compounds and their derivatives include, for example, cinnoline, 3-acetylpiperidine, Pyrazine, 2-methylpyrazine, methylazinopyrazine, pyridazine, 2-aminopyrimidine, 2-amino-4,6-dimethylpyrimidine, 2-amino-5-nitropyrimidine, 2,4,6-triamino-1,3,5-triazine, pyrrole, Pyrazole, 1-methylpyrazole, 1,2,4-triazole, indazole, benzotriazole, Quinazoline, quinoline, aminoquinoline, 3-aminoquinoline, 3-bromoquinoline, 8-carboxyquinoline, 3-hydroxyquinoline, 6-methoxyquinoline, 5-methylquinoline, quinoxaline, thiazole, 2-aminothiazole, 3,4-diazaindole, purine, 8-azapurine, indole and indolizine.

Under this is the use of the aniline derivatives as the above described basic compound in terms of viscosity stability, volatility, basicity and low side reaction particularly preferred.

There however, the aniline compounds described above are a relative one low basicity their use is in conjunction with a monomer which has an oxetane group and generally shows basicity per se, not preferred. It is preferably from the oxetane compounds Select connection which shows such a high basicity that its pKb contributes 25 ° C inside the range of 3 to 7 is limited. For example, suitably basic compounds are used, such as a Amin with an aliphatic main chain or an amine with a alicyclic main chain.

The Ink according to this embodiment The present invention will follow the exposure step heated the volatility the basic compounds should preferably be as low as possible should. In particular, the boiling point of the basic compounds lies with ordinary Pressure preferably at 150 ° C or more, more preferably at 180 ° C or more.

Around the viscosity stabilizing effect of the ink without compromising their sensitivity to sacrifice appreciably, is the content of the basic compounds or the basicity adjusting compounds preferably within the range of 1 to 30 mol% based on the total molar amount of the photoacid generator limited in the recording ink. Even more preferred is the content of the basic compounds or the basicity adjusting compounds in the range of 2 to 15 mol% the basis of the photoacid generator limited. The content and the mixing ratio These compounds in the first solution should be adjusted appropriately so as to enable that the recording ink with the second solution mixed therein is suitable Contains amounts of these compounds as defined above.

Of the Use of light-sensitive, basic compounds, which by the irradiation with light or radiation can be decomposed is preferred because the photosensitive basic compounds in the Able to minimize the deterioration of sensitivity, which occur concomitantly with the addition of basic compounds can be caused. Preferred examples of such photosensitive, Basic compounds include sulfonium compounds and iodonium compounds.

Especially preferred examples of such sulfonium compounds and iodonium compounds are triphenylsulfonium acetate, triphenylsulfonium hydroxide, triphenylsulfonium phenolate, tris-4-methylphenylsulfonium hydroxide, tris-4-methylphenylsulfonium acetate, tris-4-methylphenylsulfonium phenolate, diphenyliodonium hydroxide, Diphenyliodonium acetate, diphenyliodonium phenolate, bis-4-t-butylphenyliodonium hydroxide, bis-4-t-butylphenyliodonium acetate, bis-4-t-butylphenyliodonium phenolate, thiophenyl-substituted triphenylsulfonium acetate and thiophenyl-substituted triphenylsulfonium hydroxide.

In addition to It is also the basic compounds described above possible, to include other basic compounds in the ink. Further are onium salts as a photoacid generator employing the photoacid generator preferably should be selected from those which in are similar to the type of basic compound. For example the photoacid generator and the basic compound both from sulfonium compounds or Iodonium compounds are formed, it is possible to have excellent effects in terms of sensitivity and storage stability.

The first solution may further contain a radically polymerizable compound. The use of a radically polymerizable compound is effective for minimizing the influence of strong basicity of the printing area or the influence of acids on the pigment or on the printing area. Examples of such radically polymerizable compounds include, for example, an acrylic monomer, a methacrylic monomer, a styrene monomer and a compound having a plurality of vinyl-based polymerizable groups of these monomers. Among them are CEL2000 (trademark, DAICEL Chemical Industries, Ltd.); glycidyl methacrylate; and a compound provided with radically polymerizable as well as cationically polymerizable properties, such as ester compounds derived from vinyl alcohols and acrylic acid, methacrylic acid, etc., are advantageous in that these compounds are polymerized not only radically but also cationically can. In this case, a photo radical polymerization initiator such as Michler's ketone known as Irgar-Hardener (trademark) and benzophenone or a photo-crosslinking type radical generating agent such as bisazide may be incorporated in the ink together with the above-described radical polymerizable ones Verbindun be included. This method can also be used in a case where it is required that the ink layer after curing has excellent chemical resistance.

When next becomes the second solution in detail explained.

The second solution can by dissolving a photoacid generator in a solvent obtained using the photoacid generator is capable of producing acid upon its irradiation with light. This second solution is generally referred to as a reaction liquid.

specific examples for the photoacid generator include an onium salt, a diazonime salt, quinone diazide compounds, organic halogen compounds, aromatic sulfonate compounds, Bisulfone compounds, sulfonyl compounds, sulfonate compounds, Sulfonium compounds, sulfamide compounds, iodonium compounds, sulfonyldiazomethane compounds and mixtures of these compounds.

(wobei C1 bzw. C2 Kohlenstoff-Atome darstellen, welche eine Einfachbindung oder eine Doppelbindung bilden; R₁₀ ist ein Wasserstoff-Atom, ein Fluor-Atom, eine Alkyl-Gruppe oder eine Aryl-Gruppe; und R₁₁ und R₁₂ können gleich oder unterschiedlich sein und sind individuelle einwertige organische Gruppen mit der Maßgabe, dass diese R₁₁ und R₁₂ vereinigt werden können, um eine Ringstruktur zu bilden).Specific examples of the compounds described above include triphenylsulfonium triflate, diphenyliodonium triflate, 2,3,4,4-tetrahydroxybenzophenone-4-naphthoquinonediazide sulfonate, 4-N-phenylamino-2-methoxyphenyl diazonium sulfate, 4-N-phenylamino-2-methoxyphenyl diazonium p-ethylphenyl sulfate, 4-N-phenylamino-2-methoxyphenyldiazonime-2-naphthylsulfate, 4-N-phenylamino-2-methoxyphenyldiazoniumphenylsulfate, 2,5-diethoxy-4-N-4'-methoxyphenylcarbonylphenyldiazonime-3-carboxy-4-hydroxyphenylsulfate, 2-methoxy 4-N-phenylphenyldiazonime-3-carboxy-4-hydroxyphenylsulfate, diphenylsulfonylmethane, diphenylsulfonyldiazomethane, diphenyldisulfone, α-methylbenzoin tosylate, pyrogallotrimesylate, benzoin tosylate, MPI-103 (CAS No. [87709-41-9]; Midori Kagaku Co., Ltd.), BDS-105 (CAS No. [145612-66-4], Midori Kagaku Co., Ltd.), NDS-103 (CAS No. [110098-97-0]; Midori Kagaku Co., Ltd.). Ltd.), MDS-203 (CAS No. [127855-15-5]; Midori Kagaku Co., Ltd.), pyrogallotritosylate (CAS No. [20032-64-8], Midori Kagaku Co., Ltd.), DTS-102 (CAS No. [75482-18-7]; Midori Kagaku Co., Ltd.), DTS-103 (CAS No. [71449-78-0], Midori Kagaku Co., Ltd.), MDS-103 (CAS No. [127279-74-7]; Midori Kagaku Co., Ltd.), MDS-105 (CAS No. [116808-67-4], Midori Kagaku Co., Ltd.), MDS-205 (CAS No. [81416-37-7]; Midori Kagaku Co., Ltd.), BMS-105 (CAS No. [149934-68-9], Midori Kagaku Co., Ltd.), TMS-105 (CAS No. [127820-38-6]; Midori Kagaku Co., Ltd.), NB-101 (CAS No. [20444-09-1], Midori Kagaku Co., Ltd.), NB-201 (CAS No. [4450-68-4]; Midori Kagaku Co., Ltd.), DNB-101 (CAS No. [114719-51-6]; Midori Kagaku Co., Ltd.), DNB-102 (CAS No. [131509-55-2]; Midori Kagaku Co., Ltd.), DNB-103 (CAS No. [132898-35-2], Midori Kagaku Co., Ltd.), DNB-104 (CAS No. [132898-36-3]; Midori Kagaku Co., Ltd.), DNB-105 (CAS No. [132898-37-4], Midori Kagaku Co., Ltd.), DAM-101 (CAS No. [1886-74-4]; Midori Kagaku Co., Ltd.), DAM-102 (CAS No. [28343-24-0]; Midori Kagaku Co., Ltd.), DAM-103 (CAS No. [14159-45-6]; Midori Kagaku Co., Ltd.), DAM-104 (CAS No. [130290-80-1]] and CAS No. [130290-82-3], Midori Kagaku Co., Ltd.), DAM-201 (CAS No. [28322-50-1], Midori Kagaku Co., Ltd.), GMS-105 (Midori Kagaku Co., Ltd.), DAM-301 (CAS No. [138529-81-4] Midori Kagaku Co., Ltd.), SI-105 (CAS No. [34694-40-7]; Midori Kagaku Co., Ltd.), NDI-105 (CAS No. [133710-62-0] Midori Kagaku Co., Ltd.); EPI-105 (CAS No. [135133-12-9]; Midori Kagaku Co., Ltd.); and UVACURE1591 (DAICEL UCB Co., Ltd.). The following compounds can also be used as a photoacid generator in this case.

(where C1 and C2 carbon atoms representing which form a single bond or a double bond; R ₁₀ is a hydrogen atom, a fluorine atom, an alkyl group or an aryl group; and R ₁₁ and R ₁₂ may be the same or are different and are individual monovalent organic groups provided that these R ₁₁ and R ₁₂ can be combined to form a ring structure).

(wobei Z eine Alkyl-Gruppe darstellt)

Further, the following compounds can also be used as a photoacid generator.

(wherein Z represents an alkyl group)

wobei R6, R7, R8, R9 und R10 individuell entweder eine aromatische Gruppe oder eine funktionale Gruppe mit einem Chalcogenid-Atom und einer aromatischen Gruppe repräsentieren; C1 und C2 individuell eine aromatische Gruppe und ein Chalcogenid-Atom repräsentieren; A4 und A5 individuell Anionen-Spezies repräsentieren, welche aus der Gruppe ausgewählt werden, welche aus PF₆ ^–, SbF₆ ^–, BF₄ ^–, AsF₆ ^–, CF₃SO₃ ^–, C₄F₉SO₃ ^– und CH₃SO₃ ^– besteht; und m und n individuell eine ganze Zahl repräsentieren. Im Übrigen bedeutet der Begriff „Chalcogenid-Atom" ein Chalcogen-Atom und andere Atome, welche stärker positiv als die Chalcogen-Atome sind. Ferner bedeutet „Chalcogen-Atom", dass Schwefel-, Selen-, Tellur-, Polonium- und Iod-Atome enthalten sind.It is preferred to use onium salts as a photoacid generator, examples of the onium salts which are useful in this case include diazonium salts, phosphonium salts, and sulfonium salts containing, as a counterion, a fluoroboric acid anion, a hexafluoroantimonic acid anion, a hexafluoroarsenic acid anion, a trifluoromethanesulfonate anion, a para-toluenesulfonate anion or a para-nitrotoluenesulfonate anion. It is particularly preferable that the photo-acid generating agent has onium salts represented by the following general formulas (4) or (5) or by triazine halogen compounds. These photoacid generators are advantageous for both sensitivity and stability.

wherein R6, R7, R8, R9 and R10 individually represent either an aromatic group or a functional group having a chalcogenide atom and an aromatic group; C1 and C2 individually represent an aromatic group and a chalcogenide atom; A4 and A5 individually represent anion species selected from the group consisting of PF ₆ ^- , SbF ₆ ^- , BF ₄ ^- , AsF ₆ ^- , CF ₃ SO ₃ ^- , C ₄ F ₉ SO ₃ ^- and CH ₃ SO ₃ ^- exists; and m and n individually represent an integer. Incidentally, the term "chalcogenide atom" means a chalcogen atom and other atoms which are more positive than the chalcogen atoms, and "chalcogen atom" means that sulfur, selenium, tellurium, polonium and iodine Atoms are included.

The Onium salts, which are characterized by the general above-described Represents formulas (4) or (5) have a high curing reactivity and a excellent stability at ordinary Temperature up. Therefore, the onium salts are capable of curing the To suppress recording ink under conditions in which it does not is irradiated with light.

When the compounds represented by the above-described general formulas (4) and (5) are to be used as a photo-acid generating agent, the above-described chalcogenide atom should be used from the viewpoint of ensuring the thermal stability of the agent and its Stability water are preferably selected from sulfur and iodine atoms. In this case, the anionic species should preferably be formed from an inorganic acid, in particular PF ₆ ^- , with a view to securing a suitable acidity and thermal stability. Further, in view of improving the photosensitivity of the photoacid generator, it is particularly preferable to use hexafluorophosphate compounds having a phenylsulfonium main chain.

The Photo-acid generating agent may further, if necessary, a sensitizing dye contain. Examples of such a sensitizing dye include acridine compounds, benzofuravines, perylene, anthracene and laser dyes.

If Quinone diazide compounds used as a photoacid generator it should be possible to their salts, such as naphthoquinonediazidesulfonyl chloride and naphthoquinonediazide sulfonate.

wobei Q ein Brom-Atom oder ein Chlor-Atom repräsentiert; P repräsentiert -CQ₃, -NH₂, -NHR, -NR₂ oder -OR; R ist eine Phenyl-Gruppe oder eine kurzkettige Alkyl-Gruppe mit nicht mehr als 6 Kohlenstoff-Atomen; n ist eine ganze Zahl im Bereich von 1 bis 3; und W stellt einen aromatischen Ring oder einen heterocyclischen Ring einer Gruppe dar, welche durch die folgende allgemeine Formel (B) repräsentiert wird:

wobei Z ein Sauerstoff-Atom oder ein Schwefel-Atom repräsentiert; und R1 eine kurzkettige Alkyl-Gruppe oder eine Phenyl-Gruppe repräsentiert.Organic halogens which can be used as a photo-acid generating agent means compounds capable of forming hydrazoic halogens. Examples of such halogens are described, for example, in US Pat. Nos. 3,515,552; No. 3536489; and No. 3779778; and in German Offenlegungspatentschrift No. 2243621. In particular, U.S. Patent No. 3,515,552 discloses carbon tetrabromide, tetrabromomethylmethane, tetrabromethylene, 1,2,3,4-tetrabromobutane, trichloroethoxyethanol, p-iodophenol, p-bromophenol, p-iodobiphenyl, 2,6-dibromophenol, 1-bromo-2 -naphthol, p-bromoaniline, hexachloro-p-xylene, trichloroacetoanilide, p-bromodimethylaniline, tetrachlorotetrahydronaphthalene, α, α'-dibromoxylol, α, α, α ', α'-tetrabromo-xylene, hexabromoethane, 1-chloroanthraquinone, ω, ω, ω-tribromochinalizine, hexabromocyclohexane, 9-bromofluorene, bis-pentachlorocyclopentadiphenyl, polyvinylidene chloride and 2,4,6-trichlorophenoxyethyl vinyl ether. U.S. Patent No. 3,779,778 describes hexabromoethane, α, α, α-trichloroacetophenone, tribromotrichloroethane, and halomethyl-S-triazine. Among them, halomethyl-S-triazine such as 2,4-bis-trichloromethyl-6-methyl-S-triazine and 2,4,6-tris-trichloromethyl-S-triazine are preferable for use. More preferred examples of the organic halogen compound include those substituted by vinylhalomethyl-S-triazine, which are disclosed in U.S. Patent No. 3,987,037. This vinylhalomethyl-S-triazine compound is a photo-decomposable S-triazine having at least one trihalomethyl group and a group which is conjugated by at least one ethylenically unsaturated bond with triazine ring, said Vi nylhalomethyl-S-triazine compound is represented by the following general formula (A):

wherein Q represents a bromine atom or a chlorine atom; P represents -CQ ₃ , -NH ₂ , -NHR, -NR ₂ or -OR; R is a phenyl group or a short-chain alkyl group having not more than 6 carbon atoms; n is an integer in the range of 1 to 3; and W represents an aromatic ring or a heterocyclic ring of a group represented by the following general formula (B):

wherein Z represents an oxygen atom or a sulfur atom; and R1 represents a short chain alkyl group or a phenyl group.

Of the aromatic ring or the heterocyclic ring, both by W in general formula (A) described above can, can further substituted by other types of substituent groups. The substituent groups which are used in this case can include for example, a chlorine atom, a bromine atom, a phenyl group, a short-chain alkyl group with not more than 6 carbon atoms, a nitro group, a phenoxy group, an alkoxy group, an acetoxy group, an acetyl group, an amino group and an alkylamino group. Specific examples of Vinyl halomethyl-S-triazine compound, which is represented by the above-described general formula (A) will include the following compounds.

In addition is it also possible a compound having triazine ring useful as a photoacid generator having trihalomethane introduced into its main chain. If this triazine ring with four or more conjugated double bonds is provided, the photosensitive wavelength of Photo-acid generating agent longer to the side wavelength postponed. If an ordinary High pressure mercury lamp As a light source is to be used, therefore, the use such a compound preferred. Specific examples of one such compounds include triazine having a naphthalene substituent group.

It is also possible to use an acid ester having a photo-dissociation property as a photograph acid generating agent to use. Specific examples of such an ester include the ortho-nitrobenzyl ester of alumisilanol.

The mixing ratio of the photo-acid generator in the recording ink may be selected depending on the acid-generating efficiency of the photo-acid generator and on the amount of the color component. For example, when the concentration of the color component in the recording ink is about 5 mass%, the mixing ratio of the photo-acid generator may be restricted within the range of 1 to 10 mass parts per 100 mass parts of the total amount of the solids contained in the recording ink. If the mixing ratio of the photo-acid generator is less than 1 part by mass per 100 parts by mass of the total amount of the solids contained in the recording ink, the sensitivity of the recording ink will be deteriorated. On the other hand, if the mixing ratio of the photo-acid generator 10 As a result, an increase in viscosity of the ink is intensified with time, whereby the coating properties of the ink deteriorate and the hardness of the photo-cured ink film decreases. Therefore, the blending ratio of the photo-acid generating agent should preferably be restricted within the range of 2 to 8 parts by mass, more preferably within the range of 2 to 4 parts by mass. The mixing ratio of the photo-acid generating agent in the second solution should be appropriately adjusted so as to enable the recording ink having the first solution mixed therein to contain an appropriate amount of the photo-acid generating agent as defined above.

When the solvent to dissolve of the above-described photoacid generator, are the same solvent useful, which in the first solution can be used.

As in the case of the above-described first solution it generally desired that the second solution is prepared so that it contains no volatile component, such as For example, water and organic solvents. Organic solvents, which are used in the preparation of the starting materials such as methyl ethyl ketone, propylene glycol-based solvent and ethyl lactate however, contained in an unavoidable amount in the second solution be. Further, if the ink jet recording apparatus, for example provided with an exhaust mechanism or with a solvent recovery mechanism may contain a small amount of organic solvents in the solution be to desired To get printed matter. In this case it is under safety aspects preferably, water, alcohols, such as, for example, ethanol, propanol, or mineral oil components, such as isoper and terpene, use.

The The above-described first and second solutions are used in an ink-jet recording apparatus according to embodiment used in the present invention and mixed together immediately, before being introduced into the ink jet recording head.

The Image forming performance of the recording ink thus obtained largely depends from the chemical amplification mechanism from. In particular, an acid from a photoacid generator generated due to its irradiation with light and will be the so produced Acid due their warming diffuses, leaving the acid consequently as a catalyst for the crosslinking reaction or for the decomposition reaction acts. That is why in the case of this The presence of basic ions is a cause of deterioration the sensitivity of the ink. Therefore, care should be taken that can not be avoided that the recording ink not only in the production process of the recording ink, but also in the Production process of all components involved by a large amount basic ions is contaminated.

1 Fig. 12 schematically shows the ink-jet recording apparatus according to an embodiment of the present invention.

With reference to 1 becomes recording ink from an ink stirring tank 2 at a water column pressure in an ink jet head 20 fed. The thus-supplied ink is then discharged onto a recording medium M supplied thereto by a delivery means (not shown) to form an image. The first solution is called a color ink and the second ink is added as a reaction liquid into the ink stirring tank 2 introduced in such a way that these solutions can be mixed together in a predetermined ratio. Namely, the mixing ratio (S2 / S1) between the introduced volume (S2) of the second solution and the introduced volume (S1) of the first solution in the ink stirring container becomes 2 generally controlled to about 1/32. As explained above, the first solution contains a solvent which can be polymerized in the presence of an acid and a color component and is powered by a color ink delivery pump 6 from a color ink tank 5 delivered. The first solution may be from the color ink tank 5 at a water column pressure at the ink stirring tank 2 to be delivered. In view of the storability of the ink, this first solution should preferably contain a basic compound. On the other hand, the second solution contains a photo acid generating agent and is passed through a reaction liquid supply pump 4 from a reaction liquid container 3 delivered. The second solution may be from the reaction liquid container 5 at a water column pressure to the ink stirring tank 2 to be delivered.

Since the amounts of this first and second solution, which in the Inkrührbehälter 2 are different from each other, a container pair (color ink tank 5 and reaction liquid container 3 ) for respectively receiving these two solutions in the capacity of each other. Consequently, the ratio (V2 / V1) should be between the capacity (V2) of the reaction liquid container 3 and the capacity (V1) of the color ink tank 5 preferably smaller than the mixing ratio (S2 / S1) of these solutions in the ink stirring tank 2 be. In this way, it is possible to change the frequency of replacement of the color ink tank 5 in comparison with the replacement frequency of the reaction liquid container 3 to reduce. As a result, the frequency of stopping the printing operation for the purpose of replacing the color ink tank 5 can be reduced, thus making it possible to improve productivity. As explained hereinbelow, it has been found by the present inventors that occurrence of the viscosity increase of the ink is caused due to the thermal decomposition of the photoacid generator and that the viscosity of the color ink can not be increased as long as the color ink is kept separate. Therefore, the first solution affecting inside the color ink tank will affect 5 however, the viscosity increase is not given even if its preservation period is prolonged, and hence there is little possibility of deterioration of the image to be obtained.

The ink stirring tank 2 is inside with a stirrer blade 8th provided, which with a motor 7 thereby allowing the reaction liquid and the color ink to be stirred and mixed together, thus allowing an ink jet recording ink to be obtained. Near the ink stirring container 2 , the reaction liquid container 3 and the color ink tank 5 become a recording ink remaining detection sensor 9 , a residual reaction liquid detection sensor 10 and a color ink remaining detection sensor 11 arranged. These sensors are constructed as follows. On each side of the ink stirring container 2 , the reaction liquid container 3 and the color ink tank 5 a transparent window is arranged, onto which the beam of a LED, etc. shines. The reflected beam of this beam is then detected by these sensors, and thus the residual ink is measured based on the changes in the magnitude of the reflected beam. The recording ink remaining detection sensor 9 Further, it is also capable of not only the presence or absence of the ink residue within the ink stirring container 2 but also the level of the ink residue.

There is also a cooling fan 12 near the reaction liquid container 3 arranged to avoid that the storage temperature of the reaction liquid is increased above a higher than a predetermined temperature addition. It has been found by the present inventors that any increase in viscosity of the inkjet ink is caused by the acid generated by the decomposition of the photoacid generator under the condition of high temperatures. Therefore, generation of the acid by holding the reaction liquid container 3 at a lower temperature, thus making it possible to further suppress any increase in viscosity of the recording ink which is produced by mixing these first and second solutions. The mixing ratio of the second solution formed by the reaction liquid is not more than 3 parts by mass per 100 parts by mass of recording ink 100 which is produced by mixing this first and second solution. Therefore, even if the capacity of the reaction liquid container 3 does not increase its delivery frequency of the reaction liquid to such an extent that can cause a substantial decrease in productivity. Further, since the reaction liquid container 3 is made smaller, the reaction liquid container can 3 are kept at a low temperature using only a small amount of electric power when using a coolant such as a fan or a Peltier element.

On the downstream side of the inkjet head 20 in the direction of transmission of the recording medium, in turn, a light source 13 and a heating device 14 arranged.

The light source 13 shines light on the ink layer formed on the recording medium M to generate acid in the ink layer. As the light source 13 is it possible to have a mercury lam pe such as a low pressure, medium pressure or high pressure mercury lamp; a tungsten lamp; an arc lamp; an excimer lamp; an excimer laser, a semiconductor laser; a YAG laser; a laser system formed by a combination of a laser and a non-linear optical crystal; an electron beam irradiation apparatus; an X-ray irradiation device; etc. to use. Among these, the use of the high-pressure mercury lamp or the semiconductor laser is more preferable since these devices are advantageous in simplifying the involved system.

The heating device 14 heats the ink layer formed on the recording medium M to promote the crosslinking reaction using an acid as a catalyst. As this heating device 14 is it possible to use an infrared lamp; a hot air blower for hot air or heated air; a roller (heat roller) housing a heating element; etc. to use

As in 1 shown is a controller 101 for controlling the operation of the ink jet recording apparatus 1 with the ink jet recording head 20 connected. This control 101 is also with a power source 103 for driving the ink jet recording head 20 and an image data processing / storage device 102 for processing and storing an image formed by the ink jet recording head 20 is formed.

2 FIG. 10 is a block diagram illustrating the ink jet recording apparatus. FIG 1 illustrated. The signals from the ink residue sensors 9 . 10 and 11 be in control 101 fed. Further, the signals for controlling the operations of the reaction liquid supply pump 4 , the color ink delivery pump 6 , of the motor 7 and the cooling fan 12 out of this control 101 delivered to this.

The first solution and the second solution are controlled, as explained below, and the ink stirring container 2 fed. If the absence of the recording ink within the ink stirring container 2 by the ink remaining detection sensor 9 is detected, a predetermined amount of the second solution (reaction liquid) from the reaction liquid container 3 through the reaction fluid delivery pump 4 to the ink stirring tank 2 delivered. At the same time, a predetermined amount of the first solution (color ink) comes out of the color ink tank 5 through the color ink delivery pump 6 to the ink stirring tank 2 delivered.

The delivery amount of each of these solutions should preferably be adjusted, as explained below. Namely, these two solutions should preferably be supplied in such a manner as to control the amount of the photo-acid generator in the ink after mixing within the ink-stirring container 2 so that it falls within the range of 1 to 10 parts by mass. By providing these two solutions in this way, any viscosity increase of the ink can be minimized, and a sufficient degree of curing cure can be ensured.

In fact, however, the viscosity of the recording ink increases as soon as the second solution (reaction liquid) with the first solution (color ink) in the ink stirring container 2 is mixed. The degree of viscosity increase becomes longer as the residence time of the recording ink within the ink stirring tank becomes longer 2 greater. It is possible to increase the viscosity by minimizing the capacity of the ink stirring container 2 and by shortening the residence time of the ink after it has been mixed in the ink stirring tank 2 to suppress. However, if the amounts of these solutions to be mixed together are relatively small, it is necessary to control the supply operation of these solutions from a container pair as well as the stirring operation and the mixing in the ink stirring container 2 often perform, thus deteriorating the print productivity.

The amount of recording ink which is inside the ink stirring container 2 is to be mixed, should preferably be adjusted depending on the frequency of the printing operation. For example, in a situation where the frequency of printing operation is relatively large, the amount of recording ink to be produced should be increased to reduce the frequency of the solution feeding operation and the frequency of the stirring / mixing operation, thereby making it possible to suppress the deterioration of printing productivity , On the other hand, in a situation where the frequency of printing operation is relatively low, the amount of the recording ink to be produced should be reduced to the residence time of the ink within the ink stirring container 2 shortening, thereby making it possible to minimize any viscosity increase and to prevent the printed image from deteriorating.

These operations can be performed as follows. First, when the print command along with information regarding the data name and the copy number to the controller 101 given once are, the operating times of each of the reaction liquid delivery pump 4 and the color ink delivery pump 6 based on not only the amount of recording ink to be used, which is the data size of the image data stored in the instructed image data processing / storage device 102 are stored, the printing ratio (the ratio of the number of pixels on which ink is ejected) and the copy number, but also on the basis of the ink remaining amount, which is determined by the recording ink remaining detection sensor 9 can be specified. For example, if the amount of recording ink to be used in printing is large and the amount of ink residue inside the ink stirring container is large 2 is relatively small, the color ink and the reaction liquid through the reaction liquid delivery pump 4 and the color ink delivery pump 6 to the ink stirring tank 2 delivered. In contrast, when the amount of the recording ink to be used in printing is small and the amount of the ink residue inside the ink stirring container is small 2 is relatively large, the reaction fluid delivery pump 4 as well as the color ink delivery pump 6 not pressed at all.

In this way, by controlling the delivery amount of each of these solutions, the supply operation of these solutions from these containers as well as the stirring / mixing operation within the ink stirring container 2 suitably performed in parallel to the printing operation. Further, it is not necessary to suspend the printing operation, thus avoiding a significant deterioration of the printing productivity. In addition, it is possible to minimize any increase in viscosity of the recording ink, thus making it possible to avoid the deterioration of the printed image.

The embodiments The present invention will now be described with reference to Examples of the present invention in more detail described.

According to this embodiment In the present invention, both solutions are mixed to form the recording ink immediately before the feeding of the ink into the ink jet recording head manufacture. The recording ink, which made in this way should preferably be formulated such that the amount of color component which is included in a solvent within the range of 1 to 25 mass% to 100 mass% of the solvent limited is. To a suitable range of the content of the photo-acid generator to study in the color ink, the following experiments were carried out.

First For example, compounds EP1 and EP2 shown below were considered to be one solvent which is polymerizable in the presence of an acid.

To 50% by mass epoxy compound EP1 became 5% by mass carbon black given and mixed with it to produce the first solution.

As the photo-acid generating agent, the following compounds PAG1 and PAG2 were used and dissolved in propylene carbonate at the same mass to prepare a solution (PAG3). This photoacid generator is now commercially available as UVACURE 1591 (Trademark, DAICEL UCB Co., Ltd.)

To 50% by mass of the epoxide compound EP2 became PAG3, which was used as a Photo-acid generating agent was used, in different proportions, which in the following Table 1 are shown and mixed with the second solution (B1 to B7) produce.

Table 1

The first solution, which was previously prepared, was mixed with this second solution, to obtain ink samples (1 to 7).

The curing property and shelf life These ink samples were prepared by the following procedures examined.

Evaluation of the curing property:

First, an ink sample was dropped on the surface of a transparent film such as a PET film using a disposable syringe. This ink was then coated using a bar coater so as to obtain an ink layer having a thickness of about 4 μm, and subsequently an ultraviolet ray of 1500 mW / cm ² at a transfer speed of 25 m / min using a UV irradiation machine (HP-6, Fusion Co., Ltd.). Subsequently, the ink layer was heated for one minute at a temperature of 100 ° C to obtain a cured ink film.

Of the resulting cured Ink film was examined for its pencil hardness by a scratch test (pencil test) (JIS K 5600-5-4). This was a film with a hardness of F or more represented by a character "O", with a hardness of HB represented by a character "Δ" and with a hardness of B or less represented by a character "X", thereby increasing the curing properties the cured ink film were assessed.

Evaluation of shelf life:

The Shelf life the recording ink was judged by an accelerated test. More specifically, the ink was first allowed to stand at a temperature for 11 days of 65 ° C and then the resultant ink became at a temperature from 45 ° C using a type E viscometer (Toki Sangyo Co., Ltd.) on their viscosity checked. The shelf life The ink was calculated as follows based on the increment of the viscosity of the ink from their initial viscosity assessed.

O:

weniger als 20

Δ:

20 % bis weniger als 25

X:

25 % oder mehr, oder erzeugte Ablagerung

Incidentally, the storability of two different types of inks was evaluated, that is, one in which the first solution and the second solution were separately preserved, and the other in which these two solutions were mixed together and then preserved.

O:

less than 20

Δ:

20% to less than 25

X:

25% or more, or generated deposit

The Results are summarized in the following Table 2.

Table 2

Regarding the pencil hardness For example, samples showing H or more were considered acceptable, and in terms of shelf life were samples which Δ or showed more than rated on a practically useful level.

As In Table 2, it is in the case where the ink the mixing of the first and the second solution is subsequently preserved was required that the mixing ratio of the photo acid generator falls within the range of 2 to 4% to one for practice acceptable curing property and shelf life sure. Whereas in the case where this first and second solution were preserved separately, even if the photoacid generator in a mixing ratio in the range of 2 to 20% was added, one possible for practice acceptable curing property and shelf life sure.

A Viscosity increase of Ink after mixing these two types of solutions can by the addition of a basic compound to be inhibited, which as a viscosity stabilizer acts. For example, a compound obtained by the following Formula represents is prepared as a basic compound.

The above-described epoxy compound, a coloring component, a photo-acid generator and a basic compound were mixed together at various ratios shown in the following Table 3 to prepare Ink Samples 8 to 13.

Table 3

The curing property and the shelf life these ink samples were examined by the same procedures as described above, the results being in the following Table 4 are summarized.

Table 4

As shown in Table 4, if any no basic compound was added to the ink (the content the basic compound is zero o00), the shelf life was the ink is very bad. However, if the basic compound in a relationship of 0.2 mass% or more was the storability the ink improved. However, if the mixing ratio of the basic compound was 1 mass% or more, became the curing property the ink deteriorates. Therefore, the mixing ratio of the basic compound preferably within the range of 0.2 limited to 0.8% by mass become. It has been confirmed, that this mixing ratio on the mass of the photoacid generator based. Therefore, the mixing ratio of the basic compound should be to the photoacid generator preferably within the range of 2.5 to 10% by mass.

On The basis of the results described above has been the mixing ratio each of the photoacid generator and the basic compound in the recording ink.

(Experiment 1)

Around the cause of the viscosity increase with the time of a recording ink of the cationic curing type to investigate which is a polymerizable compound which is able to crosslink in the presence of an acid, and at least a part of the solvent justified a photoacid generator, which is capable of producing an acid to generate in response to the irradiation with light, and a Color component, the following experiment was performed.

First were the above-described compounds EP1 and EP2 with same mass mixed together to produce an epoxy resin component "a".

on the other hand was carbon black, which represents a color component, with Acrylic resin kneaded which functioned as a dispersant to prepare a mixture containing a nonionic surfactant Mittel (Sumitomo 3M Co., Ltd.) was added to a color mixture to obtain.

Then For example, the above described epoxy resin component "a" was the color mixture and PAG3, which acts as a photoacid generator works, in the circumstances (% By mass), which are shown in the following table 5 to obtain the samples "b", "c" and "e" the samples "b" and "e" prepared by first their components were mixed and then the mixture for one using a whole day and a night of a dispersion treatment a shaking device for colors was suspended.

Table 5

In Table 5 indicates the mixing ratio (mass%) of the color mixture The relationship of carbon black to the total mass of the samples.

These four samples thus obtained were placed in a darkroom at a Temperature of 65 ° C conserved to a possible Viscosity increase with time to investigate.

The speed of the viscosity increase may be attributed to the phenomenon that a polymerization reaction is initiated due to the influence of an acid generated from the decomposition of the photo-acid generator. Therefore, the rate of viscosity increase is strongly related to the rate of polymerization (reaction). For the purpose of quickly knowing the viscosity at the time the sample was preserved for 6 months at a temperature of 25 ° C, accelerated testing using higher temperature preservation was employed. The measurement of the viscosity was carried out at a temperature of 45 ° C using a type E viscometer (Toki Sangyo Co., Ltd.), the results thus obtained being shown in the graph of 3 to be shown.

As in 3 shown, samples "c" and "e" indicate an increase in viscosity. The reason may presumably be attributed to the fact that since these samples both contained a photoacid generator, a reaction between the photoacid generator and the polymerizable compound was produced, thereby increasing its viscosity. Whereas samples "a" and "b" indicated no increase in viscosity. In view of these facts, it has been confirmed that in the cases of the samples formed from a single main polymerizable compound or formed from a polymerizable compound having a pigment dispersed therein, no reaction occurs which may become a cause of its viscosity increase.

Out These results will recognize that as long as the photoacid generator and the polymerizable compound which in the presence of a Acid polymerized can be preserved separately and both components immediately be mixed together before forming a picture Recording ink, thus allowing the ink to to be discharged from an ink jet recording head possible is constant, a recording ink with a stabilized viscosity at the Ink jet recording head, thereby enabling to obtain stabilized printing properties.

in the To confirm this, the following experiment was performed.

(Experiment 2)

The above-described epoxy resin component "a", the color mixture and a photoacid generator were mixed together to obtain samples which were in the Table 6 below. In Table 6, this designates mixing ratio (Mass%) of the color mixture the ratio of the carbon black to the total mass the samples.

Table 6

In the sample "g" became PAG3 (UVACURE 1591, DAICEL UCB Co., Ltd.), which is used as a photoacid generator works, used alone.

These Samples were preserved in a darkroom at a temperature of 65 ° C. 10 days later was the sample "g" with the sample "f" in a ratio (mass%) mixed, which is shown in Table 7 below, to get a sample "h" Sample "h" was further added a temperature of 65 ° C kept in a darkroom. This sample "h" was formed from the same composition, like that of the sample "e", and consequently a recording ink of the cationic curing type was formed. by name this sample "h" was a record ink cationic curing type, which by mixing a photo acid generator with a polymerizable compound was prepared, which is a color component contained and capable of polymerizing in the presence of an acid, being this photo acid generator and these polymerizable compound were preserved separately, before they were mixed together.

Table 7

The viscosity of these samples was measured in such a manner that the viscosity of the sample "f" was measured until the 10th day, and the viscosity of the sample "h" was measured for a period starting from the 10th day to the 31st day ; and the viscosity of sample "e" was measured until day 31. The results obtained are shown in the graph of 4 shown.

As in the case of Experiment 1 described above, it was found that that sample "f", which is an epoxy resin component and a color component and did not contain a photoacid generator, even after 10 days no viscosity increase with time indicated.

As in the graph of 4 The sample "h" did not show a viscosity fluctuation for a period of 10 days, therefore, the degree of viscosity increase of the sample "h" as a whole was reduced to about 1/2 that of the sample "e".

(Experiment 3)

When next was a basic compound which acts as a viscosity stabilizer acts, and / or the basicity adjusting connection included in a color ink and then with a photoacid generator mixed to obtain a recording ink. Then the change the viscosity the ink measured over time.

Then, the above-described epoxy resin component "a", the color mixture, a fo to acidity generating agent and a basic compound (B1) are mixed together at contents (mass%) shown in the following Table 8 to obtain samples "i", "g" and "e".

Table 8

These Samples were preserved in a darkroom at a temperature of 65 ° C. 10 days later was the sample "g" with the sample "i" at a content (% By mass) which is shown in Table 9 below to get a sample "j" Sample "j" was also added a temperature of 65 ° C kept in a darkroom.

Table 9

The viscosity of these samples was measured in such a manner that the viscosity of the sample "i" was measured until the 10th day, and the viscosity of the sample "j" was measured for a period starting from the 10th day to the 21st day ; and the viscosity of sample "e" was measured until day 21. The results obtained are shown in the graph of 5 shown.

As in the case of 3 containing the results of the experiment described above 1 1, it was found that the sample "i" having an epoxy resin composition, carbon black dye and a basic compound and containing no photo acid generator did not show any viscosity increase with time even after 10 days.

These Sample "j" was with the same Composition formed as that of the sample "e", thus a recording ink of the cationic curing type was formed. Notably, this sample "j" was a cationic cationic ink curing type which by mixing a photo acid generator with a polymerizable compound was prepared, which is a color component and is capable of polymerizing in the presence of an acid, wherein this photoacid generator and these polymerizable compound were preserved separately before they were mixed together. Sample "h" showed no viscosity fluctuation for one Duration of initial 10 days on. Therefore, the degree of viscosity increase of the sample "h" as a whole became about 1/2 of that the sample "e" reduced the speed of their viscosity increase was compared from the 11th day to the rate of viscosity increase of the sample "e" from the first day reduced.

Of the the reason for this can be attributed to the fact that the acid, which results from the decomposition of the Photo-acid generating agent was generated, was neutralized by the basic compound, thus allowing was curing of the polymerizable compound which acts as a solvent acts. However, if the photoacid generator previously mixed with the basic compound, one could Neutralization continue, reducing the amount of Acid minimized was, even if a UV beam was blasted on it, taking it therefore impossible was, the ink in some cases to harden sufficiently.

Therefore, it is preferable that the photo-acid generating agent and the basic compound are separately preserved until they are mixed together immediately before discharge from an ink-jet head. Namely, the basic compound is mixed with a color ink containing a color com component, and then preserved in a color ink tank. Thereby, it is possible to allow an acid to be efficiently generated by the irradiation of ultraviolet rays, etc. while preventing the neutralization. As a result, it becomes possible to ensure a sufficient hardening degree of hardening. Thanks to this embodiment of the present invention, it is now possible to reduce the viscosity increase to 1/2 or less in comparison with the prior art. As a result, it is possible to obtain an excellent image which has only a minimal deterioration in the density of the printed image even if the ink is preserved for a long period of time in an ink-jet recording apparatus.

(Experiment 4)

Under Use of the ink, which in a darkroom at a temperature of 65 ° C for a predetermined Number of days was preserved, the curing properties the ink in the same way as explained above. The thus obtained results are shown in the following Table 10.

Table 10

According to the samples "h" and "j" it was possible how explained above, the degree of viscosity increase with Time to about 1/2 of that of sample "e." Simultaneously was confirmed, that the curing capacity of the Ink at all did not worsen.

Since a viscosity increase can be minimized in this way, the samples "h" and "j" can be fed into the ink jet recording head without any difficulty. Incidentally, it was even when the color ink and the reaction liquid each in their containers of in 1 shown ink jet recording device 1 have been preserved, it is possible to minimize the viscosity increase and thus feed it to the ink jet recording head. Namely, since its viscosity was prevented from being increased, these liquids were discharged in a stabilized amount from the ink jet recording head.

The chart of the 6 illustrates the relationship between the rate of change of the viscosity of the recording ink and the rate of change of the output volume of the ink. The rate of change of the viscosity of the ink is inversely proportional to the rate of change of its output volume. Namely, when the viscosity of the ink increases by 20%, its discharge volume decreases by 7 to 8%. In other words, when the viscosity of the ink is caused to increase by up to 20% due to its preservation, the volume of the ink to be discharged from the ink jet recording head is caused to decrease by 7 to 8% , As a result, the density of the printed image is made to deteriorate as compared with that which can be obtained before the viscosity of the ink has increased. However, as described above, according to the embodiment of the present invention, the increase of the viscosity of the recording ink to 1/2 that of the conventional recording ink can be reduced. As a result, even if the recording ink is preserved within the ink jet recording apparatus for a long period of time, it is possible to obtain an excellent printed image without substantially lowering the density of the printed image.

7 shows the influence of the preservation temperature on the viscosity increase of the recording ink. In this experiment, the sample "e" described above was preserved at three different temperatures, ie at 25 ° C, 45 ° C and 65 ° C, to measure changes in the viscosity of the ink over time confirms that, as the preservation temperature rose, the rate of increase in viscosity was correspondingly increased and that the increase in viscosity of the ink could be suppressed by preserving the ink at a lower temperature.

8th shows an ink jet recording apparatus 200 of the prior art. In this conventional ink-jet recording apparatus 200 the ink gets out of an ink tank 201 to an inkjet head 20 delivered. Although the printing operation, the irradiation with light and the heating of the ink layer can be performed in the same manner as in FIG 1 shown recording device, it is the is designed so that an ink composition containing the photo-acid generator, the solvent which can be polymerized in the presence of acids, and the color component in its entirety, are contained within an ink tank 201 is housed. If this ink composition is preserved in this state for a long period of time, this ink composition is brought into the same conditions as those of the above-described sample "e", hence its viscosity considerably increases Way to the inkjet head 20 is delivered causes an output defect to be generated.

Further, the ink tank 201 , which in this conventional ink-jet recording apparatus 200 is used, of relatively large capacity, thus requiring a large amount of electric power to keep it at a lower temperature. In addition, the size of the device is inevitably increased. It may be possible the ink tank 201 Keep with a small amount of electrical power at a lower temperature by increasing the capacity of the ink tank 201 is reduced. However, this leads to a frequent replenishment of the recording ink, thus causing the problem that the printing productivity deteriorates greatly.

at the recording device according to the embodiment In the present invention, the reaction liquid which is a photoacid generator contains in a container with low capacity houses. Therefore, the reaction liquid container can be easily chilled so any increase in viscosity of the To suppress ink without conjuring up the difficulty described above.

As explained above, is it according to one embodiment the present invention possible, a To provide ink jet printing ink, which is an excellent Shelf life has and is able to reliably print a high quality with excellent reproducibility. According to one another embodiment According to the present invention, it is possible to provide an ink-jet recording apparatus which is capable, reliable a printed matter of high quality produce with excellent reproducibility.

Claims (10)

Ink-jet printing ink comprising a solvent; and a colorant dispersed in the solvent, characterized in that the solvent comprises a color ink containing a solvent which is polymerizable in the presence of an acid and a colorant dispersed in the solvent; and a reaction liquid containing a photo-acid generating agent capable of generating an acid when irradiated with light, and which is prepared separately from the color ink, wherein the reaction liquid is preserved separately from the color ink. Ink according to claim 1, characterized in that the color ink continues to have a basic compound and / or a basicity having adjusting connection. An ink jet recording apparatus comprising: one Color ink tank with a capacity V1, which is a solvent, which is polymerizable in the presence of an acid is harbored, and a colorant therein, which contains in the solvent is dispersed; a reaction liquid container with a capacity V2 (V2 <V1), which a reaction liquid, which is a solvent and a photoacid generator harbored therein, which is dissolved in the solvent and which is capable of producing an acid when it is irradiated with light; a stirred tank, which the color ink and the reaction liquid in a mixing ratio of S1 : S2 (color ink: reaction liquid) mixed to make a recording ink; a color ink delivery agent, which feeds the color ink from the color ink tank into the stirred tank; one Reaction liquid supply means which is the reaction liquid from the reaction liquid container in feeds the stirred tank; one Ink jet recording head which records the recording a record carrier outputs; and a delivery tube containing the recording ink feeds into the recording head. An ink jet recording apparatus according to claim 3, characterized characterized in that the reaction liquid container at a temperature lower than that at which of the color ink tanks is held. An ink jet recording apparatus according to claim 3, characterized characterized in that it further comprises a cooling fan for cooling the Reaction liquid container has. An ink jet recording apparatus according to claim 3, characterized characterized in that a ratio between a capacity (V2) of the reaction liquid container and a capacity (V1) of the color ink tank (V2 <V1) smaller is as the mixing ratio (S2 / S1) between the reaction liquid and the color ink in the stirred tank. An ink jet recording apparatus according to claim 3, characterized characterized in that it further comprises an image data storage / processing device, a recording ink remaining detection monitor which detects the amount of the recording ink residue, which remains within the stirred tank, and a control device, wherein each image information and ink remainder information from the image data storage / processing device and the ink remaining detection monitor in the control device with the image information and the ink remainder information following the color ink delivery agent and the reaction liquid delivery agent be fed. An ink jet recording apparatus according to claim 3, characterized characterized in that the color ink and the reaction liquid with a relationship fed into the stirred tank which enables the recording ink, the photo acid generator in a relationship from 1 to 20% by weight. An ink jet recording apparatus according to claim 3, characterized characterized in that the color ink continues to be a basic compound and / or a basicity having adjusting connection. An ink jet recording apparatus according to claim 9, characterized in that the color ink is a basic compound and / or one the basicity adjusting compound with a ratio of 0.1 to 0.8 mass% contains.